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tcd
Apprentice
USA
72 Posts |
 Posted - Jan 20 2004 : 3:06:32 PM
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I recently changed my mag into a 12volt coil distributor . It works great except it has one problem : When I check the voltage of the battery it has a fluctuating voltage of about 12.5 V to about 40V . Now I thought it might be my alternator / votleage regulator ,but it's not because I disconnected them and then I crank the engine and the problem is still present. ... SO in other words I 've isolated the problem down to the" new coil system". I'm afraid that all of this voltage spiking might damage my voltage reg, altern, and any other grounded components. The engine is a four cylinder Continental F163 with a FairBanks Morse magneto. It's a simple engine . This is not a car engine, but it's used to turn a generator in a welding machine. ANYWAY.... the electrical system does not have any sensors,monitors,on board computers,radios,etc. NOW THAT all that has been clarified,,, can anyone tell me what is ,or what could be causing my ignition/system to behave this way,and more importanly how to stop it from doing so.
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cirvin
Nobel Prize Winner
USA
1542 Posts |
Posted - Jan 20 2004 : 3:22:20 PM
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It sounds like flyback currents from the collapsing feild on the ignition coil. Try putting a diode across the primary in souch a way that the cathode on the positve terminal and the anode on the negative terminal. That shoud absorb this kickback current.
http://daxter12.topcities.com |
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tcd
Apprentice
USA
72 Posts |
Posted - Jan 20 2004 : 3:48:19 PM
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O.k. if I do that wouldn't that interfere with the coil function. To illustrate:I did that and the engine began to falter.
TCD
Edited by - tcd on Jan 20 2004 3:49:23 PM |
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cirvin
Nobel Prize Winner
USA
1542 Posts |
Posted - Jan 20 2004 : 4:41:30 PM
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It shoudn't as long as you have the doide wired right. If you get it wrong, it will shunt all of the current away from the coil and the engine just wont run till you reverse it.
http://daxter12.topcities.com |
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tcd
Apprentice
USA
72 Posts |
Posted - Jan 21 2004 : 03:55:45 AM
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O.K. here's the deal , first I think my problem is because I'm using a electronic V O M and it's picking Up the EMI from the sparkplug wires . TO test this I placed my meter into a metal coffe can while the engine was running,and guess what !!!?? ,,the thing is now reading 13.67V with a fluctuation of about .5V which can be considered normal considering how a voltage reg and alternator work. AND when I take it out of the can.... The meter starts to fluctuate again. IN fact the closer I get the spark plugs the worser it gets. AND ABOUT the Diode, I was trying it before I started this topic. It seemed that it should work but it does'nt work that way. What it does is stop the coil's primary from collapsing and in turn if it doesn't collaspe then I don't get 20KV on the secondary. So really this diode serves as a transient supressor , allowing a way for electrons to flow back to the viod ( voltage caused by indution) when they are shoved forward by the magnetic field collapse. In other words I don't need to supress the induction,for it is because of this induction that the 12 volt ignition coil is able to create high enough voltage to cause the spark plug to spark.
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Aaron Cake
Administrator
Canada
6718 Posts |
Posted - Jan 21 2004 : 08:57:28 AM
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I measure the same thing on most ignition coils. Sounds like you've got it solved, but I don't consider it abnormal. As mentioned, it's just kickback.
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tcd
Apprentice
USA
72 Posts |
Posted - Jan 21 2004 : 2:05:45 PM
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Yeah, I'm alright,but I do have one question which is ...... Even though there's "flyback"with the 12 volt coil , once the points open (which is basicaly a switch enroute with the coil's primary) then there sould be no effect at the battery post because it's not (momentarily) connected to the battery. right?
TCD
Edited by - tcd on Jan 21 2004 2:09:11 PM |
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changing MAGNETO to 12 volt coil ignition problem
